Knife for a wood-shaving machine

ABSTRACT

A strip steel knife for wood shaving machines, wherein each blade is provided at spaced intervals with interruptions in the cutting edge to effect the separation of the shavings.

United States Patent [191 1 3,866,643 Schaefer 1 Feb. 18, 1975 [54] KNIFE FOR A WOOD-SHAVING MACHINE 1,033,202 7/1912 Selle 144/241 X [76] Inventor: Karl Schaei'er, 22 In der Lohe, Neu-Bamberg, Germany 2,564,551 8/1951 Vuzieux m 1| :41/293 Ma 22, Kirsten X [21] Appl. No.: 343,729

Primary Examiner-Andrew R. Juhasz Assistant ExaminerW. D. Bray [30] Forelgn Application Priority Data Attorney, Agent, or Firm-Steinberg & Blake Mar. 24, 1972 Germany 2214434 [52] US. Cl 144/241, 144/218, 241/293 [51] Int. Cl. B27g 13/00 [57] ABSTRACT [58] Field of Search 241/277, 293; 144/185,

A strip steel knife for wood shaving machines, wherein 83/663; 29/103, 05; 7 101 each blade is provided at spaced intervals with interruptions in the cutting edge to effect the separation of [56] References Cited the shavings.

UNITED STATES PATENTS 495,879 4/1893 Cloyd 144/241 UX 10 Claims, 4 Drawing Figures AOQ KNIFE FOR A WOOD-SHAVING MACHINE The present invention concerns a strip-steel knife (chipping knife) for wood shaving machines and a wood shaving machine cutter head incorporating the knives.

In order to avoid the high costs of grinding, adjusting and replacing the chipping knives of wood shaving machines, knives of ordinary commercial strip-steel are known, which are replaced by new knives when worn. These disposable knives, however, have the disadvantage of not producing shavings divided in the longitudinal direction of the grain, so that additional knives must also be used for producing shavings having grain lengths within a certain range, and these additional knives increase the cost of producing shavings.

Furthermore, in wood shaving machines for producing shavings of a certain grain length, knives arranged with a gap between then and profiled stripping knives are known which, however, are difficult to fix in the machine and which do not result in the desired form of shaving.

It is an object of the present invention to provide a strip steel knife for wood shaving machines which makes it possible to produce shavings having the desired length; this knife is of simple design, has a comparatively long useful life and operates satisfactorily.

Another object of the present invention is the simple and economical production of strip steel knives.

A further object of the present invention is the provision of a shaving machine cutter head provided with replaceable, economically constructed strip steel knives having a comparatively long life, whilst reducing the manufacturing costs of shavings produced with desired lengths.

According to the present invention there is therefore provided a strip-steel knife for wood shaving machines, wherein each blade is provided at spaced intervals with interruptions in the cutting edge to effect the division into chips of desired length of the shavings.

The entire knife can be readily and reliably secured in a cutter head. Due to the economical construction of the knife, it can be replaced for a new one when worn, and thus forms a cheap and easily handled disposable knife. Due to its construction, this knife is a combination of both knives hitherto necessary.

A further advantage of the present invention may be seen in the simple and economical production of strip steel knives which are cut off from an endless strip in desired lengths after production of transverse cutting portions which divide the shavings into chips of desired length.

A further advantage of the present invention is concerned with the shaving machine cutter head with in-' terchangeable strip steel knives; this has an economical design, and the knives are readily secured in the cutter head on account of their design.

Embodiments of the present invention are illustrated in the drawings, in which:

FIG. 1 shows a portion of a strip-steel knife in three views (front, side and edge) with a transverse cutting portion shaped out of the blade;

FIG. 2 shows a portion of a strip steel knife in three views, with a transverse cutting beak made by deforming a portion of the blade;

FIG. 3 shows a portion of a band-steel knife in three views, and having a different form of transverse cutting edge provided on the blade, and

FIG. 4 is a perspective view of a cutter head with replaceable blades. 7

A strip steel cutter 10, 11, 12 for wood shaving machines is provided near its cutting edge region 10a, 11a, 12a, with a plurality of interruptions of the straight cutting edge 10b, llb, 12b, arranged at fixed spaced intervals to divide the shavings longitudinally into chips of predetermined length, said interruptions forming the transverse cutting portions l3, 14, 15. The fibres of the shavings extend in the longitudinal direction of the knife, and are cut by the transverse cutting portions 13, l4, 15 to produce chips having the necessary or desired length. In the embodiment of a strip steel knofe 10 as shown in FIG. 1, each interruption 13 is formed by a punched-out notch 13a extending transversely (at right angle or acute angle) to the straight cutting edge 10b from said edge into the cutting edge region 10a, and a cutting portion 13b bent out of the plane of the knife adjacent to this slot 13a; the bentout cutting portion 13 b results in a transverse cutting portion.

In the further embodiment shown in FIG. 2 each interruption 14 of the shaving knife 11 is formed as a U or V shaped projection 14a produced in the blade 11a and produces a transverse cutting edge or beak 14 located outside the cutting edge 11b.

In another embodiment the shaving knife shown in FIG. 3 is provided with a punched-out slit 15a extending from the cutting edge 12b transversely (at a right or acute angle) to the longitudinal direction of the knife into the blade region 12a, with bent-out parts 15b extending in opposite directions resulting in a staggered blade arrangement; the bent-out blade parts 15b represent a transverse cutting portion 15.

The strip-steel knives 10, 11, 12 whose transverse cutting portions 13, 14, 15 have already been described, are made of an endless steel strip having the ground blade regions 10a, 11a, 12 a, and with transverse cutting portions 13, 14, 15 on the edge before being cut to the desired knife length; for the formation of the transverse cutting portions 13, 14, 15, the endless strip passes through a device such as a roller punch, with a pair of gearwheels meshing with each other and punching the portions 13, 14, 15 at the desired places on the straight cutting edge into the endless strip, be fore its separation into individual knives.

Furthermore, the endless strip is hardened and tempered and, if desired, reground before being separated into individual knives so that the hardening and tempering are effected after the formation of the transverse cutting portions l3, l4, l5 and then any necessary regrinding can be carried out.

The transverse cutting portions 13, 14, 15 of each knife 10, 11, 12 are preferably provided at the same distance from each other; however, they may also be arranged at different spaced intervals in the cutting area 10a, 11a, 12 a so that chips of the same or different length may be obtained with a knife 10, 11, 12.

The above-described strip-steel knives l0, l1, 12 are held interchangeably in a wood shaving machine cutter head 16, shown in FIG. 4. The cutter head 16 has the shape of a drum carrying the cutting edges of the knives 10, 11, 12 with their transverse cutting portions extending out of the cutter head casing and with their longitudinal directions slanting with respect to the axis of rotation of the cutter head 16 to form a cutting angle with the axis of rotation. The strip steel knives may be made in various lengths, and the intervals between them and the number of their transverse cutting portions 13, l4, may be varied.

The intervals between the transverse cutting portions l3, l4, 15 may be example be between 15 40 mm, preferably 30 mm.

It will thus be seen that with the structure of the invention the knives 10, 11, 12 each have a series of straight cutting edges situated along a common straight line and separated one from the next by a transverse cutting portion 13, 14, 15, respectively, extending transversely from an end of a straight cutting edge, while being integral therewith, and terminating distant from the straight cutting edge in a relatively sharp, pointed tip which serves to cut transversely for dividing the shavings produced by the straight cutting edges into chips of predetermined length. In the case of FIG. 1, the series of straight cutting edges are separated one from the next by the substantially V-shaped notch 13a, while in the case of FIG. 2 the series of straight cutting edges are separated from each other by the transversely bulging portions of the knife which form at the adjoining ends of a pair of successive straight cutting edges a pair of transverse cutting portions which join each other at the substantially sharp, pointed cutting tip 14a. In the case of FIG. 3 the series of straight cutting edges are separated from each other by slits with the knife having in the region of each slit the transversely deflected portions 15b which also terminate in the sharp cutting tips which provide the chips from the shavings which are cut with the straight cutting edges.

I claim:

1. For use in a machine for cutting wood shavings and simultaneously dividing them into chips of predetermined length, a knife having a series of straight cutting edges situated along a common straight line, said knife having at least at one end of each of said straight cutting edges a transverse cutting portion separating a pair of successive straight cutting edges from each other, formed integrally with and extending transversely from an end of a straight cutting edge, and terminating distant therefrom in a relatively sharp, pointed cutting tip, said transverse cutting portions cutting transversely across shavings cut by said straight cutting edges to divide the shavings into chips of predetermined length.

2. A knife as recited in claim 1 and wherein the knife is formed between each pair of successive straight cutting edges with a notch separating each pair of successive straight cutting edges from each other, said transverse cutting portion at an end of each straight cutting edge being located along one side of said notch.

3. A knife as recited in claim 2 and wherein said notch is of a V-shaped configuration.

4. A knife as recited in claim 1 and wherein the knife is formed between each pair of successive straight cutting edges with a bulging portion of substantially V- shaped cross section providing the adjoining ends of a pair of successive straight cutting edges with a pair of transverse cutting portions which are joined together distant from the cutting edges to form therebetween a common substantially pointed cutting tip for the joined pair of transverse cutting portions.

5. A knife as recited in claim 1 and wherein the knife is formed between each pair of successive straight cutting edges with a slit extending transversely from the cutting edges and separating them from each other with the adjoining end regions of a pair of successive straight cutting edges at said slit being deflected transversely with respect to the straight cutting edges in opposite directions to form at an end region of each straight cutting edge a transverse cutting portion terminating in said tip.

6. A knife as recited in claim 1 and wherein said straight cutting edges have substantially equal lengths.

7. A knife as recited in claim 1 and wherein said straight cutting edges respectively have different lengths.

8. A knife as recited in claim 1 and wherein said straight cutting edges have lengths of between 15 and 40 mm.

9. For use in a machine as recited in claim 1, a plurality of said knives and a rotary cutter head carrying said knives with said cutting edges and transverse cutting portions projecting beyond said head.

10. The combination of claim 9 and wherein said head has a predetermined axis of rotation and said knives extending angularly with respect to said axis of rotation. 

1. For use in a machine for cutting wood shavings and simultaneously dividing them into chips of predetermined length, a knife having a series of straight cutting edges situated along a common straight line, said knife having at least at one end of each of said straight cutting edges a transverse cutting portion separating a pair of successive straight cutting edges from each other, formed integrally with and extending transversely from an end of a straight cutting edge, and terminating distant therefrom in a relatively sharp, pointed cutting tip, said transverse cutting portions cutting transversely across shavings cut by said straight cutting edges to divide the shavings into chips of predetermined length.
 2. A knife as recited in claim 1 and wherein the knife is formed between each pair of successive straight cutting edges with a notch separating each pair of successive straight cutting edges from each other, said transverse cutting portion at an end of each straight cutting edge being located along one side of said notch.
 3. A knife as recited in claim 2 and wherein said notch is of a V-shaped configuration.
 4. A knife as recited in claim l and wherein the knife is formed between each pair of successive straight cutting edges with a bulging portion of substantially V-shaped cross section providing the adjoining ends of a pair of successive straight cutting edges with a pair of transverse cutting portions which are joined together distant from the cutting edges to form therebetween a common substantially pointed cutting tip for the joined pair of transverse cutting portions.
 5. A knife as recited in claim 1 and wherein the knife is formed between each pair of successive straight cutting edges with a slit extending transversely from the cutting edges and separating them from each other with the adjoining end regions of a pair of successive straight cutting edges at said slit being deflected transversely with respect to the straight cutting edges in opposite directions to form at an end region of each straight cutting edge a transverse cutting portion terminating in said tip.
 6. A knife as recited in claim 1 and wherein said straight cutting edges have substantially equal lengths.
 7. A knife as recited in claim 1 and wherein said straight cutting edges respectively have different lengths.
 8. A knife as recited in claim 1 and wherein said straight cutting edges have lengths of between 15 and 40 mm.
 9. For use in a machine as recited in claim 1, a plurality of said knives and a rotary cutter head carrying said knives with said cutting edges and transverse cutting portions projecting beyond said head.
 10. The combination of claim 9 and wherein said head has a predetermined axis of rotation and said knives extending angularly with respect to said axis of rotation. 